How does someone become a saint?

Nuns of the global Missionaries of Charity Order, founded by Nobel Peace Prize winner Mother Teresa, take part in a thanksgiving mass at Mother House in Calcutta, India, on Oct. 19, 2003.

DESHAKALYAN CHOWDHURY/AFP/Getty Images

Here are the steps that must be followed in the process of canonization:

A local bishop investigates the candidate's life and writings for evidence of heroic virtue. The information uncovered by the bishop is sent to the Vatican.

A panel of theologians and the cardinals of the Congregation for Cause of Saints evaluate the candidate's life.

If the panel approves, the pope proclaims that the candidate is venerable, which means that the person is a role model of Catholic virtues.

The next step toward sainthood is beatification, which allows a person to be honored by a particular group or region. In order to beatify a candidate, it must be shown that the person is responsible for a posthumous miracle. Martyrs -- those who died for their religious cause -- can be beatified without evidence of a miracle. On Oct. 20, 2003, Mother Teresa was beatified. She is now known as Blessed Mother Teresa of Kolkata.

In order for the candidate to be considered a saint, there must be proof of a second posthumous miracle. If there is, the person is canonized.

These alleged miracles must be submitted to the Vatican for verification. Sister Teresia Benedicta of the Cross was canonized in 1997 after the Vatican verified that a young girl who ate seven times the lethal dose of Tylenol was suddenly cured. The girl's family was said to have prayed to the spirit of Sister Teresia for help.

In Mother Teresa's case, her supporters are arguing that she has performed at least two posthumous miracles. In one case, a French woman in the United States broke several ribs in a car accident -- reportedly, her wounds were healed because she was wearing a Mother Teresa medallion. Another possible miracle occurred when Mother Teresa appeared in the dreams of a Palestinian girl, telling the girl that her cancer was cured.

Once a person is a saint, he or she is recommended to the entire Catholic church for veneration. Some saints are selected as patron saints, special protectors or guardians over particular occupations, illnesses, churches, countries or causes. For example, the Pope is planning on naming a patron saint of Internet users and computer programmers. Several saints are being considered, but the lead candidate is St. Isidore of Seville, who is credited with writing the world's first encyclopedia. Click here to see a full list of patron saints.